Danny Tuppeny
038a07b383
The VM service may now give us `dart-macro+package:` URIs in addition to normal `package:` URIs. These can be mapped to `dart-macro+file:` URIs in the same way that we map `package:` to `file:`. If the client editor has advertised that they support our custom Dart URIs, we can send these through to the client and let them use the analyzer-provided local sources. Otherwise, we'll treat them like other unknown sources and download them from the VM. Change-Id: If67523a615c66c469db7b1f52d281c63241eb859 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/357143 Reviewed-by: Ben Konyi <bkonyi@google.com> Reviewed-by: Helin Shiah <helinx@google.com> Commit-Queue: Ben Konyi <bkonyi@google.com>
A package used to spawn the Dart Developer Service (DDS), which is used to communicate with a Dart VM Service instance and provide extended functionality to the core VM Service Protocol.
Functionality
Existing VM Service clients can issue both HTTP, websocket, and SSE requests to a running DDS instance as if it were an instance of the VM Service itself. If a request corresponds to an RPC defined in the VM Service Protocol, DDS will forward the request and return the response from the VM Service. Requests corresponding to an RPC defined in the DDS Protocol will be handled directly by the DDS instance.
SSE Support
For certain web clients it may be preferable or required to communicate with DDS using server-sent events (SSE). DDS has an SSE handler listening for requests on /$debugHandler.
SSE and package:vm_service example
import 'package:sse/sse.dart';
import 'package:vm_service/vm_service.dart';
void main() {
// Establish connection with DDS using SSE.
final ddsChannel = SseClient('${ddsUri}\$debugHandler');
// Wait for ddsChannel to be established
await ddsChannel.onOpen.first;
// Initialize VmService using the sink and stream from ddsChannel.
final vmService = VmService(
ddsChannel.stream,
(e) => ddsChannel.sink.add(e),
);
// You're ready to query DDS and the VM service!
print(await vmService.getVersion());
}
Debugging DDS
One way to get stdout from files in DDS while debugging is to log messages to a file. You can add a method such as:
void _fileLog(String message) {
final file = File('/tmp/dds.log');
if (!file.existsSync()) {
file.createSync();
}
file.writeAsStringSync(
'''
$message
''',
mode: FileMode.append,
);
}
Then you can call _fileLog('some print debugging message'), and the log message will be written to a temp file.
To get logging output in real time, run tail -f /tmp/dds.log.